---
title: 'PostgreSQL LAST_VALUE Function'
page_title: 'PostgreSQL LAST_VALUE Function By Practical Examples'
page_description: 'In this tutorial, you will learn how to get the last value in an ordered partition of a result set by using the PostgreSQL LAST_VALUE() function.'
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---

**Summary**: in this tutorial, you will learn how to get the last value in an ordered partition of a result set by using the PostgreSQL `LAST_VALUE()` function.

## Introduction to PostgreSQL LAST_VALUE() function

The `LAST_VALUE()` function returns the last value in an ordered partition of a result set.

The syntax of the `LAST_VALUE()` function is as follows:

```css
LAST_VALUE ( expression )
OVER (
    [PARTITION BY partition_expression, ... ]
    ORDER BY sort_expression [ASC | DESC], ...
)
```

In this syntax:

### expression

The `expression` can be an expression, column, or [subquery](../postgresql-tutorial/postgresql-subquery) evaluated against the value of the last row in an ordered partition of the result set.

The `expression` must return a single value. Additionally, it cannot be a window function.

### PARTITION BY clause

The `PARTITION BY` clause divides rows of the result set into partitions to which the `LAST_VALUE()` function is applied.

If you omit the `PARTITION BY` clause, the `LAST_VALUE()` function will treat the whole result set as a single partition.

### ORDER BY clause

The `ORDER BY` clause specifies the sort order for rows in each partition to which the `LAST_VALUE()` function is applied.

### frame_clause

The `frame_clause` defines the subset of rows in the current partition to which the `LAST_VALUE()` function is applied.

## PostgreSQL LAST_VALUE() function examples

We will use the `products` table created in the window function tutorial for the demonstration:

![](/postgresqltutorial/products_product_groups_tables.png)Here are the contents of the data of the `products` table:

![](/postgresqltutorial/products-table-sample-data.png)

### 1\) Using PostgreSQL LAST_VALUE() over a result set example

The following example uses the `LAST_VALUE()` function to return all products together with the product that has the highest price:

```
SELECT
    product_id,
    product_name,
    price,
    LAST_VALUE(product_name)
    OVER(
        ORDER BY price
        RANGE BETWEEN
            UNBOUNDED PRECEDING AND
            UNBOUNDED FOLLOWING
    ) highest_price
FROM
    products;
```

![PostgreSQL LAST_VALUE over result set example](/postgresqltutorial/PostgreSQL-LAST_VALUE-over-result-set-example.png)
In this example:

- Since we omit the `PARTITION BY` clause in the `LAST_VALUE()` function, the function treats the whole result set as a single partition.
- The `ORDER BY` clause sorts products by prices from low to high.
- The `LAST_VALUE()` retrieves the product name of the last row in the result set.

### 2\) Using PostgreSQL LAST_VALUE() over a partition example

The following example uses the `LAST_VALUE()` function to return all products together with the most expensive product per product group:

```
SELECT
    product_id,
    product_name,
    group_id,
    price,
    LAST_VALUE(product_name)
    OVER(
	PARTITION BY group_id
        ORDER BY price
        RANGE BETWEEN
            UNBOUNDED PRECEDING AND
            UNBOUNDED FOLLOWING
    ) highest_price
FROM
    products;
```

![PostgreSQL LAST_VALUE over partition example](/postgresqltutorial/PostgreSQL-LAST_VALUE-over-partition-example.png)
In this example:

- The `PARTITION BY` clause divides rows by group id into three partitions specified by group id 1, 2, and 3\.
- The `ORDER BY` clause sorts products in each product group ( or partition) from low to high.
- The `RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING` clause defines the frame starting from the first row and ending at the last row of each partition.
- The `LAST_VALUE()` function applies to each partition separately and returns the product name of the last row in each partition.

## Summary

- Use the PostgreSQL `LAST_VALUE()` window function to return the last value in an ordered partition of a result set.